Disaggregation of Gas Load to Determine Gas Appliance Performance

ABSTRACT

Techniques determine if an appliance having a fixed-rate of gas-consumption is degrading over time. In one example, a flowrate of gas at a service site is obtained. The flowrate of gas is disaggregated to obtain a flowrate of gas corresponding to an appliance having a generally fixed-rate of gas-consumption. The flowrate of gas of the appliance is compared to historical gas consumption by the appliance. Based at least in part on the comparing, it may be determined that performance of the appliance has changed over time. For example, the gas consumption of a hot water tank may increase due to mineral build-up in the bottom of the tank. Responsive to the determined degradation of the appliance, warnings may be sent, repairs may be made, and/or appliance(s) may be replaced.

BACKGROUND

Smart metering devices (e.g., in the electrical, gas, water and otherutility industries) provide substantial information, which may be usedto improve the performance and/or economy of many systems, networks,smart meters, appliances and/or other devices. However, in manyinstances, the cost of sensors and the age of utility delivery systemshas resulted in less information than is desirable.

In a first example, there is no easy way for a residential customer toidentify a gas-powered appliance that is not operating at fullefficiency. Over time, gas appliances may begin to use more gas. Acommon example is a gas hot water tank, which ages over time by buildingup a layer of minerals inside the tank, which lessens the quantity ofwater that the tank can contain, and acts as a thermal insulator betweenthe flame and the water.

In a second example of insufficient information, customers may addadditional appliances to their service sites (e.g., home and businesses)as part of a transition from electricity to gas or as part of anincrease in standard of living or size of family. Accordingly, theservice capacity at the customer site may become under-sized. In manycases, this condition is not recognized by the customer or utilitycompany.

In a third example of insufficient information, an area or region of agas supply system may experience a low gas-pressure condition (e.g., dueto peak consumption). Due to the lack of sensors, the low gas-pressurecondition may not be recognized.

Without sufficient information, utility providers cannot accuratelydiagnose or remedy these or other conditions associated with utilitydelivery systems.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Thesame numbers are used throughout the drawings to reference like featuresand components. Moreover, the figures are intended to illustrate generalconcepts, and not to indicate required and/or necessary elements.

FIG. 1 is a diagram showing portions of an example utility service suchas gas or water, etc., and network of metering devices configured formetrology, data transfer, data processing, and/or other functionality.

FIG. 2 is a schematic diagram of an example utility data collectiondevice for associating gas flowrates with gas consuming loads.

FIG. 3 is a schematic diagram of an example distributed processingenvironment and a utility data collection device for associating gasflowrates with gas consuming loads.

FIG. 4 is an example chart showing bins and bin allocations of variousconsumption rates associated with various gas consuming appliances.

FIG. 5 is an example chart showing bins and bin allocations of variousconsumption rates associated with various fixed and variable consumptiongas appliances.

FIG. 6 is an example chart showing total accumulated costs associatedwith various gas consuming appliances.

FIG. 7 illustrates an example method of accumulating consumption dataindicating consumption of individual loads.

FIG. 8 illustrates a further example method of accumulating consumptiondata indicating consumption of individual loads.

FIG. 9 is a flow diagram showing an example method of determining gasappliance performance.

FIG. 9A is a flow diagram showing a second example method of determininggas appliance performance.

FIG. 10 is a graph showing normal operation of an appliance having aduty cycle including alternating periods of activity and sleep, and agas usage rate.

FIG. 11 is a graph showing operation of an appliance having shortenedperiods of sleep and/or inactivity.

FIG. 12 is a graph showing operation of an appliance having lengthenedperiods of activity and/or operation.

FIG. 13 is a graph showing operation of an appliance wherein periods ofactivity use excessive amounts of gas.

FIG. 14 is a flow diagram showing an example method of determining meteror service under-sizing.

FIG. 15 is a flow diagram showing a second example method of determiningmeter or service under-sizing.

FIG. 16 is a flow diagram showing an example method of detecting areasof low gas pressure without pressure sensors.

FIG. 17 is a flow diagram showing a second example method of detectingareas of low gas pressure without pressure sensors.

FIG. 18 is a flow diagram showing a third example method of detectingareas of low gas pressure without pressure sensors.

DETAILED DESCRIPTION Overview

The disclosure describes techniques for obtaining and processinginformation from a gas (or other type) of utility network. In a firstexample, gas usage levels for fixed-rate-consumption gas-poweredappliances are obtained. The information is processed to determine ifthe appliances are operating at full efficiency. The processing mayinclude comparison to historical usage to determine if the appliance(s)is using more gas. Environmental factors, such as air temperature andtime of year are monitored so that gas usage can be normalized, andappliance characteristics can be determined.

In a second example, gas usage levels for fixed-rate-consumptiongas-powered appliances are obtained. The information is processed toidentify if a service capacity at the customer site has or may becomeunder-sized. In many cases, this condition is not recognized by thecustomer, but may be determined at least in part because a peakgas-usage rate is consistently less than a rate associated withsimultaneous operation of all gas appliances.

In a third example, gas usage levels for fixed-rate-consumptiongas-powered appliances are obtained. In the example, a metrology devicemeasures fixed-rate-consumption of gas-powered appliances at rates belowtheir fixed usage rates. The low consumption of fixed-rate-consumptiondevices may result from a low gas-pressure condition. This lowgas-pressure condition may be further confirmed based on detection ofthe same or similar condition by a group of metering devices within aregion of a gas supply system supplied by a particular gas main, feeder,trunk, manifold, line, tank, or other common source. Such a conditionmay be addressed by techniques to re-pressurize appropriate portions ofthe gas supply network, fix leaks, and/or provide gas at greater rates.

In an example, data acquisition steps are performed by device(s) thatare specialized to measure fluid flowrates. In particular examples, thetime between reed switch closures and/or the generation and/or timing ofan ultrasonic pulse transit are performed by specialized devices (e.g.,timers, processors, etc.). Accordingly, these functions are “concrete”actions, involving mechanical actions (e.g., switch closures andpulses), and not abstract concepts. Similarly, disaggregation andhistoric comparisons are too complex to be performed by a human in atimely manner.

When the techniques discussed herein are performed locally, such actionsdecrease the amount of traffic over the network (thereby increasingnetwork performance). Such a network and/or systems are therefore moreefficient, conserve battery power (less traffic means less repeatedmessaged, etc.).

Accordingly, the techniques described herein allow utility systems torecognize and compensate for conditions such as degrading appliances,under-sized gas services, and/or regions of low gas pressure without theneed for additional sensors throughout the distribution network.

Example Networks, Systems and Techniques

FIG. 1 shows portions of an example system 100, comprised of portions ofa gas-supply system and portions of a communications network. In examplesystems, the topology of the communication networks may or may not matchor directly correspond to the topology of the distribution networks. Inone example, portions of a gas supply system may use portions of acommunication network of an electrical or water supply system. The gassupply system may include gas supply equipment, gas pipes for gastransport, metering at each customer site, valves and other controldevices and control circuitry, as required. The communication networkmay include a plurality of nodes, some of which are in communicationwith one another. A node may be part of a communications systemassociated with a gas supply system, and may include a one- or two-wayradio, a processor, memory and/or other components. At least some nodesmay be associated with a device of a gas supply system, such as a gasmeter. In some examples, the communication network may be comprised ofone or more individual networks (e.g., mesh networks, star networks,etc.). FIG. 1 illustrates an example in which the nodes are organized inone or more mesh networks.

In the example, a root node (e.g., the router device 102) may be inradio frequency (RF) communication with one or a plurality of nodes inthe mesh network. The router device 102 may communicate, via one or morenetworks 104 (e.g., wired or wireless, such as a cellular or RFconnection), with a central office having a server 106 (e.g., remotefrom the nodes 108-122), which may include one or more computingdevices, such as servers associated with a utility company, or servershaving a role in managing, owning, providing, or using the communicationnetwork and the nodes and devices of, and/or associated with, thatnetwork. In some examples, a server 106 in the central office may managemany networks, and may use one or more router devices to communicatewith devices in each network. Examples of such networks may includeolder and newer nodes, which may use different technologies.

In the example of the communications network, a node (e.g., node 108)has a plurality of one-hop neighbors (e.g., nodes 110-120), each ofwhich may be connected to a same or a different gas supply pipe. In theexample, the network of the example system 100 may be a mesh network,including a plurality of devices that relay information upstream anddownstream, such as between a router device and a plurality of nodesusing parent nodes to relay data for child nodes.

The node 108 is part of the mesh network of the example system 100. Inthe example shown, the node 108 is the parent node to a child node 110that is downstream from the node 108. That is, child node 110 depends onits parent, node 108, to relay messages upstream (e.g., to the routerdevice 102) and downstream (e.g., from the router device 102).

In the example shown, a plurality of one-hop upstream neighbors to node108 are shown, including nodes 112-120 which are reached by “one hop”through the RF mesh network. Node 110 (a child of node 108) is a one-hopneighbor but is downstream of node 108. While nodes 112-120 are shown asone-hop upstream neighbors of node 108, the number of one-hop upstreamneighbors for any node may be fewer or much larger, depending on networklayout, geometry, RF conditions, etc. Accordingly, the example of FIG. 1is for purposes of illustration and explanation and is not intended toconvey any limitations to the systems and/or techniques described.

A region of additional mesh network 124 of the mesh network of theexample system 100 is representative of a potentially large number ofnodes. The nodes may be configured to relay data upstream and downstreamfor the nodes 108-122 that are located downstream of the additional meshnetwork 124. While not all nodes are shown individually, the meshnetwork may have many hundreds or many thousands of nodes, and thedrawings shown are accordingly simplified to better convey theillustrated concepts.

In some examples of the network of the example system 100, each node maycontain various components. In the example of node 120, a metrologydevice 126 and a data processing component 128 are representative ofsuch components. The metrology device 126 may be solid-state, and maycalculate gas flowrate in part from the input of an ultrasonic sensor,transducer or other device. The metrology device 126 may be mechanical,and upon measurement of a unit-volume of gas may close a switch or senda signal. An additional example of such components is shown in FIG. 2.The data processing components of some or all of the nodes in thenetwork may be configured to include modules for enablement of variouspurposes and techniques 130. Example purposes and techniques 130include: gas appliance performance calculations; gas service sizing andunder-sizing calculations; and/or low gas pressure calculation anddetermination.

Example Disaggregation of a Gas Flow

Existing gas meters may totalize gas usage over a period of time, suchas per hour or per month, and record this usage as an hourly or monthlytotal consumption amount. However, such meters fail to provideinstantaneous consumption information and fail to associate consumptionwith individual consuming appliances.

The techniques described herein for gas flowrate determination may beimplemented by an enhanced or smart gas meter (e.g., an endpoint),central/headend office or other location. The techniques may accumulategas usage information and determine various consumption rates associatedwith gas consuming loads (e.g., fixed-rate consumption gas appliances).As an example, an enhanced gas meter measures gas flowrates, categorizesthe measured gas flowrates, associates the categorized gas flowrateswith gas consuming loads and/or appliances and outputs a result toinclude gas consumption data with the gas consuming loads. In thisexample, gas flowrates of individual gas consuming loads and gasflowrates indicating simultaneous operation of multiple individual gasconsuming loads may be recognized. Gas consuming appliances (e.g., gaswater heater, gas furnace) may be associated with gas consumption sothat a consumer may track a total consumption or a total cost ofoperating individual appliances over a measurement period.

Various gas consuming appliances, such as a furnace or water heater, usean approximately constant rate of gas while they operate. Other gasconsuming appliances, such as a stove, electrical generator, or clothesdryer, may use a variable rate of gas depending on a number of burnersin operation and/or a degree flowrate to the respective burners (in thecase of the stove), a size of an electrical load being supplied (in thecase of the generator), or a temperature setting (in the case of theclothes dryer). Pilot lights have a relatively low but constant rate ofgas consumption. By recording an amount of gas used at variousconsumption rates, information may be extracted that indicates how muchgas is used by individual gas appliances.

A usage profile may be collected, such as by a utility company, and madeavailable to a customer via a web site, an application, an in-homedisplay, on a monthly bill, or the like. As an example, a customer orutility company may associate each gas consuming appliance withaccumulated gas flowrate data. A customer may then monitor estimatedcosts associated with individual gas consuming appliances as well asusage changes over time of individual gas consuming appliances. As anexample, a customer may discover that a water heater is consuming moregas than was normal in the past, which may be attributable to a calciumbuild-up in the tank of the water heater. As another example, a consumermay discover that a gas furnace is consuming more gas than was normal inthe past, which may indicate that the furnace needs servicing. A chart,table, graphic, or other information may be provided to a customerindicating how individual gas appliances contribute to total overall gasconsumption.

In some examples, the flowrate of gas may be disaggregated based atleast in part on historical data. In an example, the historical data mayindicate a change in gas consumption of an appliance over time, such asdue to an ageing process of a hot water tank. By recognizing and/oranticipating the degradation, a disaggregation algorithm may morequickly recognize the appliance as a fixed-rate consumer of gas.Accordingly, disaggregating the flowrate of gas may include the use ofhistorical gas usage data and/or recognizing fixed-use appliances fromprevious disaggregation processes, even when the appliance hasexperienced a change in gas consumption over time. Such use ofhistorical data may speed the disaggregation process. Recognition of thegradual changes of gas use by fixed-rate of consumption appliances mayalso speed the disaggregation process.

Example Environments for Disaggregation of a Gas Flow

FIG. 2 is a schematic diagram of example architecture 200 of a utilitydata collection device for associating gas consumption and/or gasflowrates with gas consuming loads and/or gas appliances. As shown inexample architecture 200, utility data collection device (UDCD) 202(e.g., a smart utility gas meter) includes a consumption meter 204. Asan example, consumption meter 204 may provide a signal or other dataindicating measurement of a specific quantity of gas. The signal mayalso indicate a specific meter type or other information. Consumptionmeter 204 may be a mechanical rotary meter to include a residential orcommercial diaphragm meter, an electro-mechanical meter, or any othertype of meter that measures flow quantity (e.g., consumption quantity)over time, and provides corresponding consumption data.

Encoder-transceiver (ET) module 206 may be configured to processconsumption data measured by consumption meter 204 and to measure and/ordetermine flowrates (e.g., gas flowrates). As an example, ET module 206may be an encoder-receiver-transmitter (ERT®). ET module 206 may connectto, or integrate with, consumption meter 204 via a direct mount, aremote mount, an integrated construction, etc. ET module 206 andconsumption meter 204 are shown in FIG. 2 as separate parts of utilitydata collection device 202 for simplicity of discussion, but couldalternatively be combined or remotely connected.

As shown in FIG. 2, ET module 206 contains metrology module 208 forreceiving and processing consumption data from consumption meter 204.Metrology module 208 may be configured to convert the consumption dataprovided by consumption meter 204 to specific units (e.g., cubic feet)and format the consumption data for processing, transmission and/orstorage. Metrology module 208 may include memory, one or more processorsand one or more modules for processing the consumption data fromconsumption meter 204.

ET module 206 may also include communications (i.e., comms) module 210.Comms module 210 allows UDCD 202 to communicate with external sources,such as a utility company central office, a mobile wireless meterreading device, a consumer, a user, or the like. Comms module 210 may beconfigured to format data, such as into frames or data packetsassociated with one or more communications protocols, and facilitateone-way or two-way communications with external entities. As an example,comms module 210 may include a radio frequency (RF) transceiver andantenna (not shown) to facilitate wireless communications, a power linecommunications (PLC) transceiver (not shown) for communication via apower line, a direct communication interface, etc. Metrology module 208and comms module 210 may be communicatively coupled to each other and/orcommunicatively coupled to processing environment 212.

In the example of FIG. 2, the processing environment 212 is integratedinto ET module 206. Processing environment 212 may include one or moreprocessors 214 and memory 216. Memory 216 may comprise computer-readablestorage media that includes, but is not limited to, RAM, ROM, EEPROM,flash memory, cache memory, or other hardware storage devices orhardware-based memory technology. Processing environment 212 mayinclude, or be part of, an application-specific integrated circuit(ASIC) or other suitable hardware logic. Memory 216 may store a varietyof modules, such as message processing module 218, rate measurementmodule 220, rate association module 222 and data logging module 224.Separate from, or integrated with memory 216, is consumption log 226 forstoring data associated with processing environment 212.

Message processing module 218 processes messages between UDCD 202 and autility company, consumer, user, or the like. Message processing module218 may process various configuration commands to configure, forexample, ET module 206. Message processing module 218 may be configuredto respond to messages or commands to convey information to users. As anexample, message processing module 218 may process external messages orcommands received by comms module 210, and format data or responsemessages for transmission using comms module.

Rate measurement module 220 may be configured to process consumptioninformation, such as data received from metrology module 208, todetermine various consumption rates (e.g., instantaneous gas flowrates).As an example, rate measurement module 220 is configured to associate atime interval between known amounts of consumption at consumption meter204, such that consumption rates may be measured over time intervals.Rate measurement module 220 may be configured to process consumptionamounts provided by consumption meter 204 via metrology module 208 todetermine gas flowrates at consumption meter 204. Rate measurementmodule 220 may be configured to pass measured consumption rates to rateassociation module 222.

Rate association module 222 may be configured to categorize measuredconsumption rates (e.g., gas flowrates) determined or measured by ratemeasurement module 220. As an example, rate association module 222 mayaccumulate measured gas flowrates in bins having ranges of gas flowratesthat bracket the bins. For example, rate association module 222 maycategorize gas flowrates into bins having different ranges, such as60-80 BTUs, and 80-100 BTUs, etc. As such, rate association module 222categorizes consumption rates received from rate measurement module 220into one or more bins, each bin bracketed by a range of consumptionrates.

Rate association module 222 may be configured to accumulate gasconsumption data at various consumption rates in bins and sumconsumption data within each of the various consumption rate bins over ameasurement period. For example, the rate association module 222 may suma total amount of gas used in a range of 80-90 cubic feet per hour (orin a range of 100-110 cubic feet per hour, etc.) over a billing ormeasurement period. Rate association module 222 may be configured todetermine consumption rate trends and configure a number of bins,locations of bins and/or ranges of consumption rates that bracket thebins (e.g., bin distribution). Rate association module 222 may beconfigured to relate quantities of accumulated consumption data atvarious consumption rates to associate gas flowrates with gas consumingloads. As an example, rate association module 222 may detectaccumulation of consumption data in multiple different bins, andassociate the detected accumulation with gas consuming loads based ondetermining relative amounts of accumulated consumption data.

As an example, rate association module 222 may be configured to detectaccumulation of consumption data at a boundary of two adjacent bins, andadjust bins such that the accumulated consumption data is accumulated ina single bin of the two adjacent bins. As another example, rateassociation module 222 may assign multiple bins of a plurality of binsto accumulate consumption by a consumption load in the assigned multiplebins.

As an example, if a residence has a water heater with a pilot light, afurnace with an electronic ignition, and a gas cooking stove, rateassociation module 222 may be configured to learn various consumptiondistribution rates for these gas consuming appliances such that a numberof bins, bin sizes (i.e., width or range of consumption rates thatbracket the bin) and/or bin locations are configured and adjusted tobest accumulate consumption data for each gas consuming appliance. In anembodiment, rate association module 222 evaluates consumption data tooptimize bin distribution.

Rate association module 222 may also be configured to optimize (e.g., asize and/or a location of) one or more bins that accumulate gasconsumption associated with simultaneous operation of multiple gasappliances. As an example, a water heater may cycle on while a furnaceis off, and a furnace may cycle on while the water heater is off.However, at times, both the water heater and furnace may operatesimultaneously. In this case, rate association module 222 optimizes abin location and range of gas flowrates that bracket the bin toaccumulate gas flowrates indicating simultaneous operation of both thefurnace and water heater while operating simultaneously. In anembodiment, rate association module 222 evaluates consumption data toresolve the contribution of the furnace and the water heater associatedwith the bin having accumulated gas flowrates indicating simultaneousoperation of both the furnace and water heater. This allows forgeneration of a chart that resolves a total consumption and/or a totalcost associated with the simultaneous operation of two or moreindividual gas consuming loads into constituent individual gas consumingloads.

As another example, if a consumer were to add an additional gasconsuming load (e.g., gas appliance), rate association module 222 mayre-allocate the distribution of bins to optimize an accumulation ofconsumption data of the prior and the additional gas consumingappliance(s). As another example, if a consumer were to replace a gasconsuming appliance with a new, more energy efficient model thatoperates in a lower range of gas flowrates, rate association module 222may re-allocate bin distribution to optimize an accumulation of gasconsumption data of the new gas consuming appliance in an associatedbin. As another example, if a consumer removes a gas appliance, the rateassociation module 222 may re-allocate bin distribution to optimize anaccumulation of gas consumption data of the existing remaining gasappliances.

As another example, a consumer may have a gas appliance that is designedto operate at a fairly constant gas flowrate, but for some reason, suchas a defect, the appliance starts operating at a different gas flowrate.Rate association module 222 is configured to re-allocate bindistribution to track the different gas flowrate of the potentiallydefective gas appliance. Upon receiving a chart showing this differentgas flowrate, a consumer could determine that the gas appliance may havebecome defective and take appropriate action. Rate association module222 may be configured to flag that the change has occurred.

Data logging module 224 is configured to store consumption data inconsumption log 226. As an example, as consumption at measured gasflowrates are accumulated in bins, data logging module 224 stores theaccumulated consumption data in consumption log 226. Data logging module224 may be configured to format the consumption data, such that theaccumulated consumption data associated with bins can be provided inchart form to a utility company, consumer, user, or the like. As anexample, data logging module 224 formats the consumption data tofacilitate generating a chart showing a total consumption and/or a totalcost over a measurement period associated with individual gas consumingappliances. Therefore, a utility company, consumer, user, or the likemay access information from consumption log 226 to determine totalconsumption associated with individual gas appliances.

ET module 206 may include computer-readable media. Computer-readablemedia may include two types of computer-readable media, namelycomputer-readable storage media and communications media.

Computer-readable storage media (e.g., memory 216, consumption log 226)includes volatile and non-volatile, removable and non-removable mediaimplemented in any method or technology for storage of information suchas computer readable instructions, data structures, program modules, orother data. Computer-readable storage media, such as consumption log226, includes, but is not limited to, RAM, ROM, EEPROM, flash memory orother memory technology, CD-ROM, digital versatile disks (DVD) or otheroptical storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices, or any other non-transmissionmedium that can be used to store information for access by a computingdevice.

In contrast, communication media may embody computer readableinstructions, data structures, program modules, or other data in amodulated data signal, such as a carrier wave, or other transmissionmechanism. As defined herein, computer-readable storage media does notinclude communication media.

FIG. 3 is a schematic diagram of example architecture 300 of using autility data collection device (e.g., smart gas meter) to associate gasflowrates with gas consuming loads in a distributed processingenvironment. As shown in example architecture 300, utility datacollection device (UDCD) 302 (e.g., a smart utility meter) includesconsumption meter 204, as described with respect to FIG. 2 and ET module304.

ET module 304 includes metrology module 306, comms module 210 andmessage processing module 218, as described with respect to FIG. 2.Using message processing module 218, ET module 304 may respond tocommands to provide consumption data obtained, for example, fromconsumption meter 204. Metrology module 306 may be configured to convertthe consumption data provided by consumption meter 204 to specific units(e.g., cubic feet) and format the consumption data for processing,transmission and/or storage. Metrology module 306 may include memory,one or more processors and one or more modules (not shown) forformatting the consumption data from consumption meter 204. Metrologymodule 306 may be configured to provide consumption data to processingenvironment 308. As an example, metrology module 306 may provideconsumption data to processing environment 308 using comms module 210 inresponse to a message request, or at various time durations.

In example architecture 300, processing environment 308 is shown asseparate from ET module 304. Processing environment 308 may include adistributed processing environment in direct or indirect communicationwith UDCD 302, such as via comms module 210. As an example, processingenvironment 308 may be located at a utility company central office, ordistributed among multiple offices or other locations. Processingenvironment 308 is shown in FIG. 3 to have components includingprocessor(s) 214, memory 216, message processing module 218, ratemeasurement module 220, rate association module 222, data logging module224 and consumption log 226, as described with respect to FIG. 2.Various components of processing environment 308 may be located in ETmodule 304. As an example, metrology module 306 and/or ET module 304 maycontain some or all of the functionality associated with ratemeasurement module 220, as well as data logging module 224 andconsumption log 226.

Thus, processing environment 308 may be configured to providefunctionality comparable to the functionality provided by processingenvironment 212, described herein with regard to FIG. 2.

Example Bin Allocation of Consumption Rates

FIG. 4 is a diagram showing an example chart 400 of a distribution ofbins and bin allocations at various consumption rate ranges. Thehorizontal x-axis 402 illustrates example bins 1-19 associated withvarious ranges of consumption rates.

The vertical y-axis 404 measures accumulated consumption data over ameasurement period, such as a day, a month or the like. As illustratedin FIG. 4, bin 1 is bracketed on x-axis 402 by a range of consumptionrates of 0-2 cubic feet per hour. In the context of the example of FIG.2, rate measurement module 220 detects a consumption rate of gas in therange of approximately 0.25 cubic feet per hour, where rate associationmodule 222 allocates that consumption rate to bin 1 that brackets 0.25cubic feet per hour with a range of consumption rates of 0-2 cubic feetper hour. As an example, bin 1 may be associated by a consumer, utilitycompany or third-party entity with a pilot light 406. Thus, rateassociation module 222 accumulates consumption data that falls in therange of 0-2 cubic feet per hour. This data may be summed to measure atotal accumulated consumption over a measurement period, as illustratedby the height of pilot light 406 as measured on y-axis 404.Additionally, rate association module 222 may store data associated withan amount of gas consumed in the bin 1 range of 0-2 cubic feet per hourover a measurement period within the consumption log 226.

As illustrated in example chart 400, bin 8 is associated with a range ofconsumption rates of 80-90 cubic feet per hour of gas. In a similaraspect to bin 1, rate measurement module 220 detects a consumption ratein the range of 80-90 cubic feet per hour, and rate association module222 accumulates the associated consumption rate data in bin 8. Theconsumption associated with bin 8 may be attributable to gas waterheater 408. As an example, water heater 408 has pilot light 406.Therefore, since water heater 408 consumes gas at a substantiallyconstant rate when it is cycled on, rate association module 222accumulates the amount of gas consumed over time in bin 8.

Bin 10 is illustrated in FIG. 4 as associated with a range ofconsumption rates of 100-110 cubic feet per hour. In the example of FIG.1, rate association module 222 accumulates the amount of gas consumedwithin a range of consumption rates of 100-110 cubic feet per hour,which may be displayed in bin 10. The accumulated amount of gas consumedin bins is measured along y-axis 404. As an example, gas consumptionoccurring within a consumption rate associated with bin 10 may beassociated with gas furnace 410.

Bin 18 is illustrated in FIG. 4 as associated with a range ofconsumption rates of 180-190 cubic feet per hour. In the example of FIG.1, rate association module 222 accumulates the amount of gas consumedwithin a range of consumption rates of 180-190 cubic feet per hour,which may be displayed in bin 18. The total amount of gas consumed asaccumulated in bin 18 is measured along y-axis 404. As an example, gasconsumption occurring within a consumption rate associated with bin 18is associated with pilot light 406, water heater 408 and gas furnace 410running simultaneously as all gas-consuming and/or operating appliances412.

Rate association module 222 may be configured to resolve all consumingappliances 412 into constituent individual gas-consuming loads. As anexample, based on a relative analysis of total consumption on y-axis 404of pilot light 406, water heater 408 and furnace 410, rate associationmodule 222 may be configured to resolve all consuming appliances 412into constituent components of pilot light 406, water heater 408 andfurnace 410. Other bins (e.g., 2-7, 9, 11-17 and 19) are associated withranges of corresponding consumption rates as shown on x-axis 402 whereno appreciable consumption data has been accumulated.

FIG. 5 is a diagram showing an example chart 500 of a distribution ofbins according to various consumption rate ranges. Vertical y-axis 404,as shown in FIG. 4, measures total consumption associated with each bin.Horizontal x-axis 502 illustrates bins 1-16 associated with variousranges of consumption rates. In a manner that differs from example chart400 of FIG. 4, FIG. 4 illustrates a different bin allocation ordistribution along x-axis 502. In one example difference, bin 3 isassociated with a consumption rate of 20-70 cubic feet per hour.

Rate measurement module 220 may detect consumption of gas at variableconsumption rates in the range of 20-70 cubic feet per hour associatedwith a variable gas consuming appliance, such as a gas cooking stove504. The rate association module 222 may accumulate these variableconsumption rates over bins 3-6 of FIG. 4, and data logging module 224stores these variable consumption rates in consumption log 226. Autility, consumer, third party entity, or the like, may then analyzethis data and recognize that it results from an appliance havingvariable gas rate consumption. Having recognized the nature of theconsumption, the bins may be reorganized or adjusted as shown in FIG. 5.

As an example, a utility, consumer, third party entity, or the like, maysend a command to ET module 206 or 304 to allocate bins as shown in FIG.3. As another example, rate association module 222 may be configured toanalyze data in consumption log 226 to learn that these variableconsumption rates are persistent. As such, rate association module 222may reallocate bins on x-axis 402 to create a new bin 3, as shown inFIG. 4, associated with consumption rates of variable gas consumingappliance 504. Additionally, rate association module 222 may beconfigured to vary other bins on x-axis 502. As an example, rateassociation module 222 varies other bins on x-axis 502 based on ananalysis of consumption data or observed consumption rates from ratemeasurement module 220. Rate association module 222 may widen or narrowa width of consumption rate ranges in bins to better capture consumptionat consumption rates of individual appliances with corresponding bins.In one example, a comparison of FIGS. 3 and 4 shows a consolidation ofvarious bins. As another example, based on evaluated or observedconsumption rates, rate association module 222 may merge unused bins9-13 on x-axis 402 into a single bin. As required, rate associationmodule 222 may allocate any number of bins and any range of consumptionrates (e.g., widths) of bins. If a consumer acquires a new gas consumingappliance that consumes gas according to a range of bin 11 (i.e.,140-150 cubic feet per hour), rate association module 222 accumulatesconsumption data associated with bin 11, and may merge unused bins 8-10and bins 12-14 into individual respective bins.

FIG. 5 shows that bin 15 is associated with a consumption range of180-190 cubic feet per hour. In the example of FIG. 2, the rateassociation module 222 measures the amount of gas consumed within arange of 180-190 cubic feet per hour over time in bin 15. The currenttotal amount of gas consumed in bin 15 is measured along y-axis 404.FIG. 5 shows that gas consumption within a consumption range associatedwith bin 15 results from simultaneous operation of pilot light 406,variable gas consuming appliance 504, water heater 408 and gas furnace410. Other bins (e.g., 2, 4, 6, 8-14 and 16) are associated with rangesof corresponding consumption rates as shown on x-axis 402. FIG. 5 showsonly one bin, bin 15, used to accumulate all simultaneous consumption.However, depending on the number of individual gas consuming loads, aswell as their consumption rates, rate association module 222 mayallocate multiple bins representing simultaneous consumption of othercombinations of various gas consuming loads. As another example, due tothe variability of variable gas consuming load 504, rate associationmodule 222 may determine to not include variable gas consuming load 504in all consuming and/or operating appliances 506 running simultaneously.

Based on the loads that the rate association module 222 determines toinclude in all consuming appliances 506 running simultaneously, rateassociation module 222 may be configured to resolve which amount ofconsumption along axis 502 is attributable to each consuming load. As anexample, rate association module 222 may be configured to indicate whatpercentage of all gas-consuming loads 506 running simultaneously isattributable to each of the pilot light 406, the water heater 408 andthe furnace 410. Thus, rate association module 222 may be configured toresolve all consuming loads 506 into constituent individual gasconsuming loads, to indicate portions attributed to loads 406, 408 and410.

FIG. 6 is a diagram showing an example chart 600 of total accumulatedcosts on axis 602 associated with various gas consuming appliances.Chart 600 represents a usage profile collected by the utility and madeavailable to the customer through a website, a printed bill or invoiceor an in-home display. An appliance may be associated with each step ofthe flowrate, such as pilot light 406, stove 504, water heater 408,furnace 410, and simultaneous usage 506 by a homeowner, utility company,user, etc.

As an example, a 100,000 BTU furnace uses gas at a rate of 100 cubicfeet per hour. A 65,000 BTU stove uses gas at a variable rate of 25-65cubic feet per hour. An 80,000 BTU water heater uses gas at 80 cubicfeet per hour. A pilot light uses 0.25 cubic feet per hour. FIG. 6 showsan example of how consumption in cubic feet as well as cost can bedisplayed for a home with a water heater with a pilot light, a gas stoveand a furnace with electronic ignition.

Consumption log 226 may store additional information for use by autility, consumer, third-party entity, or the like. As an example,consumption log 226 may contain data that associates time-of-day withdistinct consumption rates (e.g., pilot light 406, water heater 408,furnace 410 and combination 506) such that data may be presented to auser on example chart 500 indicating various times of day that variousgas consuming appliances consumed gas.

FIGS. 4-6 show examples of use of a single bin to show an amount of gasconsumed at different rates. In an alternative, the rate associationmodule 222 may allocate two or more bins to accumulate consumption forone or more of pilot light 406, stove 504, water heater 408, furnace 410and all simultaneous consumption 506. As an example, in the alternative,bins 1-19 shown in FIG. 4 may each include multiple bins, such as 5 ormore sub-bins. Rate association module 222 may be configured to select anumber and location of sub-bins to adjust a number, location and widthof bins associated with x-axis 402 in FIG. 4.

Example Methods for Determining Consumption Rates

FIG. 7 illustrates an example method 700 of determining gas consumingloads associated with various consumption rates. Method 700 is describedwith reference to the example architecture 200 of FIG. 2 forconvenience. However, method 700 is not limited to use with the examplearchitecture 200 of FIG. 2 and may be implemented using otherarchitectures and devices, such as example architecture 300 shown inFIG. 3.

Method 700 begins at block 702, with measuring gas flowrates. As anexample, rate measurement module 220 measures gas flowrates atconsumption meter 204.

At block 704, the measured gas flowrates are categorized according toone or more levels or gas flowrate ranges. In one example, the rateassociation module 222 of FIGS. 2 and 3 categorizes gas consumption atmeasured gas flowrates into corresponding bins. In the example, the ratemeasurement module 220 may measure a rate of 85 cubic feet/hour and rateassociation module 222 may categorize the measured gas flowrate with bin5 in FIG. 5, which is bracketed by gas flowrates of 80 and 90 cubicfeet/hour, such that bin 5 has a width of gas flow ranges of 10 cubicfeet/hour. Rate association module 222 thus accumulates consumption ofgas (e.g., records data) around 85 cubic feet/hour in bin 5 in FIG. 5.Thus, rate association module 222 accumulates consumption data at themeasured gas flowrates in bins having ranges of gas flowrates thatbracket the bins, such that the categorizing the measured gas flowratescomprises associating the measured gas flowrates with ranges of gasflowrates. As an example, rate association module 222 may categorize gasflowrates of individual gas consuming appliances and gas flowrates ofsimultaneous operation of two or more of the individual gas consumingappliances into corresponding ranges of gas flowrates.

At block 706, categorized gas flowrates are associated with gasconsuming loads. As an example, based on detecting a quantity of gasconsumed by a gas consuming load at a rate of about 85 cubic feet/hour,rate association module 222 may determine that bin 5 in FIG. 5, having arange of gas flowrates of 80-90 cubic feet/hour, is associated with thegas consuming load. As another example, based on a quantity of gasconsumed around 105 cubic feet/hour, rate association module 222 maydetermine that bin 7 in FIG. 5 is associated with a gas consuming load.Rate association module 222 may then determine that a quantity of gasconsumed around 185 cubic feet/hour is associated with bin 15 in FIG. 5and is attributable to simultaneous operation of consuming loads 408 and410 in FIG. 5. Therefore, rate association module 222 recognizes gasflowrates of individual gas consuming loads and gas flowrates indicatingsimultaneous operation of at least two of the individual gas consumingloads.

At block 708, a result of the associating the categorized gas flowrateswith gas consuming loads may be output. As an example, the result outputincludes accumulated gas flowrate data associated with the gas consumingloads. As another example, the result includes accumulated consumptionat gas flowrates of individual gas consuming loads and accumulatedconsumption at gas flowrates indicating simultaneous operation of two ormore of the individual gas consuming loads, accumulated in a pluralityof bins or ranges of gas flowrates. As an example, the result mayinclude usage data such that the usage data of at least two of the gasconsuming appliances includes data obtained while at least two gasconsuming appliances were simultaneously operational.

The result of data associated with consumption accumulated in bins overa measurement period, such as illustrated in FIGS. 4-6, may be output.In the context of the example of FIG. 2, message processing module 218may receive a command from a utility company, consumer, or the like, toprovide accumulated consumption data in bins. In response to thecommand, data logging module 224 may format the data, such that the datais provided for transmission via comms module 210. The ET module 206 maybe configured to periodically or a-periodically provide the result ofaccumulated consumption data in the bins.

At block 710, gas consuming appliances are associated with at least asubset of the gas consuming loads. As such, the categorized gasflowrates may be associated with gas consuming loads that compriseassociating the categorized gas flowrates with gas consuming appliances.A user interface may be presented to a consumer, allowing the consumerto associate gas consuming appliances with one or more of the gasconsuming loads. As such, an association may be received, throughoperation of the user interface, of one or more gas consuming applianceswith at least one gas consuming load. Alternatively, gas consumingappliances may be associated with one or more of the gas consuming loadsbased at least in part on known consumption rates of the gas consumingappliances.

At block 712, the result output may be used to generate a chart based atleast in part on the result showing total consumption and/or total costover a measurement period associated with individual gas consumingappliances. As an example, data logging module 224 may be configured togenerate the chart associated with individual gas consuming appliances.The chart may resolve total consumption and/or the total cost associatedwith the simultaneous operation of two or more of the individual gasconsuming loads into constituent individual gas consuming loads. Asanother example, the result output by data logging module 224 may beused by an external entity to generate the chart showing totalconsumption and/or total cost over a measurement period associated withindividual gas consuming appliances that resolves simultaneous operationof the two or more of the individual gas consuming appliances intoconstituent individual gas consuming appliances. In the case where gasconsuming appliances have been associated with gas consuming loads, thecharts may be annotated to show consumption of individual gas consumingappliances.

FIG. 8 illustrates an example method 800 to determine gas consumingloads associated with various consumption rates. Method 800 is describedwith reference to the example architecture 200 of FIG. 2 forconvenience. However, method 800 is not limited to use with the examplearchitecture 200 of FIG. 2 and may be implemented using otherarchitectures and devices, such as example architecture 300 shown inFIG. 3.

As an example, bins (e.g., ranges of gas flowrates) used to accumulateconsumption data at various consumption rates may be predefined with adefault bin distribution, such as illustrated in FIG. 4. Duringoperation, upon determining gas consumption at various gas consumptionrates, rate association module 222 may adjust a range of gas consumptionassociated with one or more bins to better capture consumption atvarious consumption rates.

At block 802, a number of ranges of gas flowrates (e.g., number of bins)are determined, locations of ranges of gas flowrates (e.g., binlocations) are determined and a width (e.g., bin width) of each of theranges or gas flowrates are determined. At block 804, bins may beadjusted by rate association module 222 based on the determined numberof bins, locations of bins and/or ranges of gas flowrates that bracketeach of the bins. In the example of FIG. 4, bins 1-19 may not be alignedor best adjusted to accumulate consumption of pilot light 406, waterheater 408, furnace 410 and simultaneous operation of appliances 412.Therefore, rate association module 222 may be configured to change thenumber of bins, change the location of the bins and change the range ofgas flowrates that bracket the bins to best accumulate consumption ofpilot light 406, water heater 408, furnace 410 and simultaneousoperation of appliances 412.

At block 806, changes of categorized gas flowrates associated with thegas consuming loads are tracked and the categorizing of the measured gasflowrates may be adjusted based on the tracked changes. In the contextof the example of FIG. 4, assume that due to a defect or otherphenomenon, the rate of gas consumption of water heater 408 changes tobe between bins 7 and 8 or bins 8 and 9. In this example, rateassociation module 222 may be configured to adjust bins to track thechanged consumption rate of water heater 408. As an example, rateassociation module 222 may change a location of bin 8 by shifting it inthe direction of the changed consumption rate of water heater 408. Asanother example, rate association module 222 may remove a bin to widenbin 8 to best accumulate consumption at the changed consumption rate ofwater heater 408. Rate association module 222 may reduce a range ofother bins to account for a shift or widening of the ranges of bin 8. Asan example, data logging module 224 may be configured to flag that aconsumption rate has changed to alert a consumer.

At block 808, a change in a number of gas consuming loads is detected.As an example, the change in the number of gas consuming loads may bereflected in an output and/or a chart as a changed number of gasconsuming appliances associated with gas consuming loads. As an example,rate association module 222 may adjust bins to accommodate a removal oraddition of one or more gas consuming loads. Referring again to FIG. 5,assume that variable gas consuming load 504 was newly added. As shown inexample FIG. 5, rate association module 222 has reduced the number ofbins (relative to FIG. 4) and has changed the range of gas flowratesthat bracket or surround bin 3 (e.g., changed the width of bin 3) tobest accommodate accumulation of consumption data of variable gasconsuming load 504. Therefore, rate association module 222 may beconfigured to detect a change in a number of the gas consuming loads,and in response to detecting the change in the number of the gasconsuming loads, determine at least one of a new number of the bins, newlocations of the bins or new widths of ranges of gas flowrates thatbracket the bins.

At block 810, the gas flowrates of simultaneous operation of two or moreof the individual gas consuming appliances are resolved to indicateconsumption by each individual gas consuming appliance. As an example,referring back to FIG. 3, data logging module 224 may log accumulatedconsumption of pilot light 406, water heater 408, furnace 410 andsimultaneous operation of appliances 412 in consumption log 226. Datalogging module 224 may be configured to log the accumulated gasflowrates of the individual gas consuming loads and the accumulated gasflowrates indicating simultaneous operation of two or more of theindividual gas consuming loads in consumption log 226. Rate associationmodule 222 may evaluate consumption log 226 to resolve the simultaneousoperation of two or more of the individual gas consuming appliances toindicate consumption by each appliance and update at least one of anumber, a location, or ranges of gas flowrates that bracket the bins ofthe plurality of bins. Thus, at block 812, rate association module 222may be configured to evaluate consumption log 226 to perform aspects ofthe methods described in blocks 802-810 above.

Example Recognition of Appliance Degradation at Service Point

FIGS. 9 and 9A shows an example methods 900 and 900A of determining gasappliance performance and/or performance degradation over time. While anorder of the blocks of the method is shown, the order of execution maybe changed, and blocks may be omitted, without departing from the methodas disclosed or claimed. The methods may be performed by any device,such as those having a processor and memory. In several examples, themethods may be performed by a smart gas metering device. The method maybe performed by one or more computer devices such as a server 106 withinthe central office, a cloud-based computing service, or other computingdevice, etc. Portions of the methods may be performed by a headenddevice (e.g., the server 106 at the central office), a service point(e.g., node 108) or performed by a combination of these or otherdevices. In an example, the methods may be performed by execution ofsoftware and/or stand-alone or cooperating application(s) running on asmart meter, central office server, and/or other device. In the examplesof FIG. 1, the techniques 130 may include and/or be configured as anapplication able to execute the methods. In the examples of FIGS. 2 and3, the methods may be performed by software stored in memory device 216and executed by a processing device and/or processor 214.

Gas appliances may degrade over time, which can result in increased gasconsumption. In an example of appliance degradation, a gas-powered hotwater tank may acquire a layer of minerals over time. The layer may tendto insulate water in the tank from the gas heat source. Additionally,significant cost is associated with heating the mineral layer, whichserves no purpose. Accordingly, the gas used by the appliance increasesover time as the mineral layer is formed. Note that (except fordegradation over time) the gas-powered hot water tank is a regular orfixed-rate consumer of gas. In contrast, other appliances do not havesubstantially fixed or regular consumption of gas. In the example of astove, different numbers of burners may be used and/or set to differentheat levels.

In an example, the techniques described herein provide a means toidentify increased consumption and provide information to customersand/or a utility company. Such information indicates an opportunity torepair or replace currently used appliances for more efficientappliances. In an example, an electronic notice may be sent to anin-home display, indicating the need to consider appliance-replacement.In a further example, a notice may be sent to the appliance-owningcustomer, perhaps including an appliance advertisement, coupon, rebate,and/or buy-back offer.

At block 902, flowrate data of gas delivered to a service point isobtained. The source of the flowrate data may be a metrology device of agas meter (e.g., metrology device 126 of node 120 of FIG. 1). In anexample, flowrate data may be obtained by a processor of a meteringdevice (e.g., the data processing component 128 of node 120 of FIG. 1).In a further example, the flowrate data may be obtained by a processorof a server 106 at the central office from a node associated with ametering device. Alternatively, the flowrate data may be generated byany metering device and/or metrology device. It may be sent to, and/orbe received or obtained by, any data processing device.

Block 904 shows a first example by which the flowrate may be obtained.In the example, the metrology device of a gas meter may be configured tomeasure cumulative consumption and not flowrate. As the gas is consumed,a mechanical device moves to measure a unit volume of gas and results ina switch closure to indicate that the full unit volume has beenmeasured. Accordingly, each switch closure may be interpreted asconsumption of the unit quantity of gas, which may be added to a runningtotal that may be recorded and stored in memory. However, the timebetween successive switch closures may be used as, or used to determine,flowrate. In the event that a single appliance is using gas, the unitvolume of gas and the period of time between switch closures (or numberof closures within a period of time, etc.) may indicate flowrate of theparticular appliance. Accordingly, a baseline flowrate of an appliancemay be associated with a time between switch closures of a metrologydevice of the service point. This may be repeated for a plurality ofappliances as needed.

Block 906 shows a second example by which the flowrate is obtained. Inthe example, the flowrate is measured at a smart gas meter. The flowratemay be obtained by the smart gas meter from a metrology device (e.g., asolid-state device) of the smart gas meter.

At block 908, having been obtained or received by a processor, theflowrate data may be disaggregated. The disaggregation process mayresult in determination of a baseline flowrate of an appliance having afixed gas-consumption rate at the service point. In an example, thedisaggregation may be performed by operation of all or part of thesystem of FIG. 1, devices of FIGS. 2 and/or 3, the techniquesillustrated by FIGS. 4-6 and/or the methods of FIGS. 7 and 8. Thedisaggregation techniques receive flowrate data and output or identifyone or more baseline gas flowrates associated with one or moreindividual appliances, such as a hot water tank or furnace, havingfixed-rates of gas consumption (i.e., “regular” rates of gasconsumption). Thus, identified baseline consumption levels may beassociated with regular consumers of gas, i.e., appliances that have afixed gas consumption rate, such as a hot water tank. Baselineconsumption levels are not identified for variable consumers of gas,such as stoves, emergency generators, BBQs, and/or many gas fireplaces.In an example, a disaggregation function may be adjusted based at leastin part on historical data indicating a change in gas consumption of theappliance over time. Thus, as gas use by the appliance changes, such asdue to degradation of the appliance, the new gas use rate may be used torecognize the appliance in the disaggregation process.

In the example of block 910, the disaggregation function and/or processmay be based at least in part on historical data indicating a change ingas rate consumption of the appliance over time. That is, by recognizingincremental and/or small changes in the historical use of gas by anappliance, the disaggregation process may recognize the appliancedespite its (perhaps incremental) changing gas consumption. Suchrecognition may speed the disaggregation process, and may reduce theconsumption of battery power in some systems.

At block 912, the baseline flowrate may be normalized for environmentalfactors to obtain a normalized baseline flowrate. In an example, theconsumption of a hot water tank may be normalized to account forseasonal differences in incoming water temperature. The water temp couldbe a relative difference (e.g., current temperature vs. historicaltemperature(s)) based on season, or the water temperature could be ameasurement of the actual water temperature (e.g. measured by IntelisWater meter or similar) relative to air temperature. In an example, thenormalization lessens the risk of identifying an efficient hot watertank as inefficient, when in fact the hot water tank is heating coolerincoming water in the winter. In a second example, the normalizationlessens the risk of identifying an inefficient hot water tank asefficient, when in fact it is heating warmer incoming water in thesummer. In a further example, baseline flowrate may be normalized basedat least in part using outside temperatures at the time the baselineflowrate was disaggregated from the flowrate of gas.

In an example of a gas meter using a mechanical metrology device, eitherthe flowrate (if it has been calculated) or the time between switchclosures (if this value is being used as the benchmark of appliancecondition) may be adjusted to normalize the gas usage. The adjustmentmay be made based on environmental conditions (e.g., temperature) andmay then allow comparison to historical usage flowrates that may also berecorded using time between switch closures and/or using flowratesderived from time between such closures. In an example, normalizing thebaseline flowrate may include calculating differences in gas required toadjust for different incoming water temperatures and/or calculatingdifferences in gas required to adjust for different ambient airtemperatures.

In a still further example, normalizing the baseline flowrate of theappliance may be based at least in part on contemporary and/orhistorical use of other appliances at other respective service points.Accordingly, if appliances at other service sites are using more or lessgas and/or are deviating from their historical values, the baselineflowrate may be normalized based at least in part on those events. In anexample, a value indicating normalized gas use at a customer's site maybe increased in the normalization process if customers' appliances atother site(s) are using more gas, or the reverse.

In some example, the normalizing of block 912 may be omitted.Accordingly, in block 912 the comparison may be of actual flowrates andenvironmental conditions may be considered—or not—in other manners. Forexample, flowrates associated with similar environmental conditions maybe compared at block 914, thereby considering environmental conditionswithout the need to normalize. In an example, gas use by a hot watertank may be compared to gas use by the tank when the incoming water isnearly the same temperature. Alternatively, an adjustment may be made inthe comparison if the temperature is different.

At block 914, the normalized baseline flowrate may be compared tohistorical levels of gas usage of an appliance. The historical levels ofgas usage may be stored in absolute terms and/or in normalized(according to environmental conditions at the time of gas consumption)terms. In an example, the historical levels of gas usage may be storedon a cloud-based environment, the central office having a remote server106, on the memory device 216 of a metering device and/or encodertransceiver module 206, etc. In an example of a gas meter usingmechanical metrology device, the flowrate may be compared to historicalflowrates by comparing a normalized time between switch closures tonormalized historical time between switch closures. However, if flowratehas been calculated based on the time between switch closures, theflowrate may be compared to historical flowrates. In an example ofcomparing the normalized baseline flowrate to historical normalizedbaseline flowrates, the current values for the elements 1102, 1202,and/or 1302 (discussed with respect to FIGS. 11-13 below) may becompared to historical levels of these element(s). In a further example,the historical levels of gas usage may include maintaining disaggregateddata of individual appliances over time.

When comparing the normalized baseline flowrate of an appliance at aservice site to historical usage, in some instances it is helpful tocompare the normalized flowrate to historical use of appliances at otherservice sites. Thus, the process of comparing may include comparing thenormalized baseline flowrate to the historical levels of gas at theservice point and to historical levels of gas use by appliances at otherservice point(s).

Accordingly, the normalization process at block 912 and the comparisonprocess at block 914 may in some examples consider data from otherservice sites. Such data use may prevent flagging of an appliance asdegraded, when in fact conditions at other service sites may suggestother factors caused the appliance to use more gas.

At block 916, based at least in part on the comparison of block 914, itis determined if gas consumption by the appliance has increased overtime and if that increase indicates appliance degradation. In anexample, if the gas increase (if any) is greater than a threshold value,then appliance degradation is indicated. Example actions of block 916are shown and/or described by examples illustrated in FIGS. 10 through13, wherein gas use by an appliance increases over time.

In a first example 1000 of block 916 seen in FIG. 10, an expected dutycycle and/or time 1002 between appliance operation is shown. The time1004 of appliance operation (i.e., duration of operation) and flowrate1006 during appliance operation are shown. Accordingly, if thenormalized baseline flowrate (from block 910) is consistent with (e.g.,within a threshold value of): the time of operation 1004; the timesbetween operations 1002; and the gas flowrate during operation 1006,then the appliance may be considered to be in good health and/or at anappliance health level at a time at which the method 900 becameoperational.

In a second example 1100 of block 916 seen in FIG. 11, the time betweenoperations 1102 is shortened (e.g., by more than a threshold value) whencompared to one or more historical values (e.g., time between operations1002). Shortening by more than a threshold value when compared tohistorical value(s) may indicate increased gas consumption by theappliance. While not required, the duration of appliance operation 1004and the gas used 1006 during operation remains as seen in FIG. 10.Accordingly, if the normalized baseline flowrate (from block 910) has atime between operations 1102 that is shortened by more than a thresholdvalue, the condition of the appliance may be considered to have degradedsince the appliance was new and/or since the method 900 becameoperational.

In a third example 1200 of block 916 seen in FIG. 12, the time ofoperation 1202 of the appliance has lengthened (e.g., by more than athreshold value) when compared to one or more historical values (e.g.,time of operation 1004). When time of operation 1202 exceeds historicalvalue(s) of the time of operation 1004 gas consumption by the appliancemay have increased. While not required, the time 1002 between operationsof the appliance and the gas used 1006 during operation remains as seenin FIG. 10. Accordingly, if the normalized baseline flowrate (from block910) has a time of operation 1202 that has lengthened by more than athreshold value, the condition of the appliance may be considered tohave degraded since the appliance was new and/or since the method 900became operational.

In a fourth example 1300 of block 916 seen in FIG. 13, the flowrate 1302of gas used in the operation of the appliance has increased (e.g., bymore than a threshold value) when compared to one or more historicalvalues (e.g., flowrate 1006). This may include a steady rate of gas usedin the operation of the appliance. Alternatively, it may be determinedif a peak instantaneous gas flowrate measured during periods ofcontinuous gas use by the appliance is increasing with respect tohistorical values. When flowrate 1302 (either steady-state orinstantaneous peak) exceeds historical value(s) of the flowrate 1006,gas consumption by the appliance may have increased. While not required,the time 1002 between operations of the appliance and time 1004 duringoperation remains as seen in FIG. 10. Accordingly, if the normalizedbaseline flowrate (from block 910) has an increased gas flowrate 1302during operation of the appliance, the appliance may be considered tohave degraded somewhat since the appliance was new and/or since themethod 900 became operational.

Accordingly, example operations of block 916 are understood withreference to FIGS. 10-13. FIG. 10 shows preferred operation of a healthyappliance (or the health of the appliance at the onset of method 900).FIGS. 11-13 show example conditions that may be checked at block 916when making comparisons to historical flowrates. Note that while theexample conditions are each shown in isolation in FIGS. 11-13, in someinstances of operation of method 900 more than one of the examples ofappliance degradation shown in FIGS. 11-13 could be simultaneouslypresent. Thus, one or more of: aspects of shortened time betweenoperation 1102; longer periods of operation 1202; and/or higher gasflowrate during operation 1302 may be present simultaneously in anappliance as it degrades over its lifecycle.

At block 918, based at least in part on the comparing blocks 912 and/or914, it is determined if the normalized baseline flowrate of gas (e.g.,as determined at block 910) used by the appliance has increased overtime. In an example, aspects of shortened time between operation 1102,longer periods of operation 1202, and/or higher gas flowrate duringoperation 1302 may be considered, as discussed with respect to FIGS.10-13. Any one or more of the characteristic changes 1102, 1202 and/or1302 may be used to indicate increased gas consumption by an applianceover time.

Block 920 shows examples by which it may be determined if a change inflowrate indicates appliance degradation. In one example, threshold(s)may be used to compare to one or more of: a change in gas flowrateresulting from decreased time between appliance operations; increasedtime of appliance operations; increased gas flowrate during operations;and/or combinations of these. In a further example, increased gas use bythe appliance may be determined by use of statistical techniques such asstandard deviation.

At block 922, an action is performed in response to determining that anappliance has increased its gas consumption and is operatinginefficiently. In a first example, a customer owning the appliance isnotified (e.g., by mail, email, message sent to an in-home display ordisplay linked to a smart gas meter, etc.) that the appliance hasdegraded, and that repair or replacement is recommended. In a secondexample, the appliance is repaired. In a third example, the appliance isreplaced. In a fourth example, an alarm notification may be provided toa device, such as an in-home display of the customer or a server of autility company or third-party service company.

Further Example of Recognition of Appliance Degradation at Service Point

FIG. 9A shows an example method 900A of determining gas applianceperformance and/or performance degradation over time. As appliances age,they may begin to consume more gas. By obtaining a gas flowrate of aresidence or business a disaggregation process may be utilized todetermine fixed-rate gas-consuming appliances. By comparing thefixed-rate of such an appliance to historical records, it may bedetermined if the appliance is consuming more gas. Example ways that anappliance may consume more gas are shown in FIGS. 10-13. If more gas isbeing consumed, notifications may be sent and/or repair or replacementmay be performed.

At block 930, a flowrate of gas is obtained by a device at a servicesite. At block 932, several examples are shown by which data may beobtained. In an example, the data may include and/or be based on timebetween switch closures in a mechanical gas meter. In a second example,the data may include and/or be based on a number of switch closures overa period of time. In a third example, the data may be obtained by orfrom a metrology device that can directly measure the flowrate of gas.

At block 934, the flowrate of gas may be disaggregated to obtain arepresentation of a flowrate of gas corresponding to one or moreappliances having a generally fixed-rate of gas-consumption. An exampleof such an appliance may be a hot water tank. Some furnaces havemultiple burners, and may be recognized in the disaggregation process astwo or more fixed-rate of gas-consumption appliances.

In an example, the disaggregation function may be adjusted based atleast in part on historical data indicating a change in gas consumptionof the appliance over time. In the example, the disaggregation functionmay be configured to verify old disaggregation results in less time thanis required to do a completely new disaggregation. However, as a gasflowrate of a fixed-rate appliance grows due to appliance degradation,known disaggregation functions may not recognize the current appliance(that currently uses somewhat more gas) as the previously identifiedappliance (that previously used somewhat less gas). However, a moreadvanced disaggregation function may recognize the possibility that aslightly larger flowrate may indicate operation of the same appliancewhich previously had a slightly smaller flowrate, and may therebyaccelerate operation of the disaggregation function.

At block 936, the representation of the flowrate of gas corresponding tothe appliance is compared to a representation of historical gasconsumption by the appliance. In the example of block 938, therepresentation of historical gas consumption by the appliance (for usein the comparison) may be selected based at least in part onenvironmental conditions. In the example of block 940, compensation maybe made for differences in environmental conditions at times the twoflowrates were measured.

At block 942, based at least in part on the comparing, it may bedetermined that performance of the appliance has changed over time. Inthe example of block 944, the determination of block 942 may be based atleast in part on one or more of the techniques or characteristic shownin FIGS. 11-13.

At block 946, based at least in part on the determination, anotification may be generated. The notification may include informationabout the appliance and its increased gas usage.

At block 948, the notification may be transmitted to another device. Inthe example of block 950, the device may be an in-home display, cellphone application, email message to a resident of the service site, thegas-supplying utility company, or other device and/or entity.Alternatively, or additionally, the appliance may be repaired orreplaced, depending on circumstances.

Further Example of Recognition of Appliance Degradation at Service Point

The following numbered clauses include additional examples ofdetermining gas appliance performance and/or performance degradationover time.

1. A method, comprising: obtaining a flowrate of gas by a device at aservice site; disaggregating the flowrate of gas to obtain arepresentation of a flowrate of gas corresponding to an appliance havinga generally fixed-rate of gas consumption; comparing the representationof the flowrate of gas corresponding to the appliance to arepresentation of historical gas consumption by the appliance;determining, based at least in part on the comparing, that performanceof the appliance has changed over time; generating a notification, basedat least in part on the determination; and transmitting the notificationto another device.

2. The method of clause 1, wherein the disaggregating, comparing anddetermining are performed at: a server at a central office; or a dataprocessing component of the device at the service site.

3. The method of clause 1, wherein obtaining the flowrate of gas at theservice site comprises: obtaining data regarding time between switchclosures; obtaining data regarding a number of switch closures overtime; or obtaining data from a metrology device that can directlymeasure the flowrate of gas.

4. The method of clause 1, wherein the representation of historical gasconsumption by the appliance comprises: a record of gas consumption anda record of corresponding environmental conditions.

5. The method of clause 1, additionally comprising: selecting therepresentation of historical gas consumption by the appliance based atleast in part on environmental conditions.

6. The method of clause 1, wherein comparing the representation of theflowrate of gas corresponding to the appliance to the representation ofhistorical gas consumption by the appliance comprises: compensating fordifferences in environmental conditions at times the two flowrates weremeasured.

7. The method of clause 1, wherein determining that performance of theappliance has changed over time comprises: determining that a durationof a period of usage has changed compared to the representation ofhistorical gas consumption by the appliance.

8. The method of clause 1, wherein determining that performance of theappliance has changed over time comprises: determining that a timebetween periods of usage has changed compared to the representation ofhistorical gas consumption by the appliance.

9. The method of clause 1, wherein determining that performance of theappliance has changed over time comprises: determining that an amplitudeof usage has changed compared to the representation of historical gasconsumption by the appliance.

10. The method of clause 1, wherein determining that performance of theappliance has changed over time comprises: determining that a peakamplitude of usage has changed compared to the representation ofhistorical gas consumption by the appliance.

11. The method of clause 1, wherein the transmitting the notification toanother device comprises transmitting the notification to an in-homedevice.

12. A headend device, comprising: a processor; a network connection; andone or more computer-readable media storing computer-executableinstructions that, when executed by the processor, configure the headenddevice to perform operations comprising: obtaining a flowrate of gas;disaggregating the flowrate of gas to obtain a representation of aflowrate of gas corresponding to an appliance having a generallyfixed-rate of gas consumption; comparing the representation of theflowrate of gas corresponding to the appliance to a representation ofhistorical gas consumption by the appliance; determining, based at leastin part on the comparing, that performance of the appliance has changedover time; and sending a message indicating repair or replacement of theappliance, consistent with the determining, is indicated.

13. The headend device as recited in clause 12, wherein disaggregatingthe flowrate of gas comprises: adjusting a disaggregation function basedat least in part on historical data indicating a change in gasconsumption of the appliance over time.

14. The headend device as recited in clause 12, wherein the appliance islocated at a first service point, and wherein the comparing additionallycomprises: comparing the representation of the flowrate of gascorresponding to the appliance to a representation of gas consumption byan appliance at a second service point.

15. The headend device as recited in clause 12, wherein therepresentation of historical gas consumption by the appliance comprisesat least one of: a representation of ambient air temperature; arepresentation of incoming gas temperature; and a representation ofincoming water temperature.

16. One or more computer-readable media storing computer-executableinstructions that, when executed by one or more processors, configure acomputing device to perform acts comprising: obtaining a flowrate ofgas; disaggregating the flowrate of gas to obtain a representation of aflowrate of gas corresponding to an appliance having a generallyfixed-rate of gas consumption; comparing the representation of theflowrate of gas corresponding to the appliance to a representation ofhistorical gas consumption by the appliance; determining, based at leastin part on the comparing, that performance of the appliance has changedover time; generating a notification, based at least in part on thedetermination; and transmitting the notification to another device.

17. One or more computer-readable media as recited in clause 16, whereindetermining that performance of the appliance has changed over timecomprises: determining that a duration of a period of usage has changedcompared to the representation of historical gas consumption by theappliance.

18. One or more computer-readable media as recited in clause 16, whereindetermining that performance of the appliance has changed over timecomprises: determining that a time between periods of usage has changedcompared to the representation of historical gas consumption by theappliance.

19. One or more computer-readable media as recited in clause 16, whereindetermining that performance of the appliance has changed over timecomprises: determining that an amplitude of usage has changed comparedto the representation of historical gas consumption by the appliance.

20. One or more computer-readable media as recited in clause 16, whereinthe representation of historical gas consumption by the appliancecomprises at least one of: a representation of ambient air temperature;a representation of incoming gas temperature; and a representation ofincoming water temperature.

Example Recognition of Under-Sized Gas Capacity at Service Point

FIGS. 14 and 15 shows an example methods 1400 and 1500 to determine if agas service is adequately sized. Gas service sizing may be based atleast in part on gas pipe diameter, gas pressure, etc. While an order ofthe blocks of the method is shown, some variation in the order ofexecution may be made without departing from the scope of the method asdisclosed or claimed. The methods may be performed by any device, suchas those having a processor and memory. In several examples, the methodsmay be performed by a smart gas meter, which may be associated with node108 of FIG. 1. The method may be performed by computer devices such as aserver 106 within the central office, a cloud-based computing service,or other computing device, etc. The methods may be performed at aheadend device, a service point or performed by a combination ofdevices. In an example, the method 1400 may be performed by execution ofsoftware or an application running on a smart meter, central officeserver, and/or other device. In the examples of FIG. 1, the techniques130 may include, and/or be configured as, an application able to executethe methods. In the examples of FIGS. 2 and 3, the methods may beperformed by software stored in memory device 216 and executed by aprocessing device and/or processor 214.

Customers may upgrade appliances and/or add appliances that consumenatural gas. As a result, the gas required by a service site canincrease over time. The techniques discussed herein identify servicesites having an inadequate or under-sized gas flow capacity. Thetechniques provide notification to upgrade the gas service beforegas-supply under-sizing degrades the customer's experience.

In an example, a system is configured to perform the techniquesdiscussed herein. The system may receive gas consumption data associatedwith an amount of gas consumed at a service point. The data may bedisaggregated to determine at least two single-appliance baseline (orreference) rates of gas consumption. The baseline rates are flowrates ofappliances that have a generally fixed consumption rate. The system thendetermines if the at least two appliances can be operatedsimultaneously. The at least two single-appliance baseline rates of gasconsumption may be added together, to thereby produce a sum indicating acombined gas flowrate of the fixed consumption rate devices connected tothe gas service. After a period of time greater than a first thresholdvalue (e.g., 6 months or a year), if the system fails to detect aflowrate of gas measured at the service point that is within a secondthreshold value of the sum it is likely that the two or more fixed-rateappliances operated simultaneously while using less gas than the sum oftheir baseline rates. The first threshold may be several months induration, during which the system tries to recognize all of the fixedconsumption rate appliances operating simultaneously. The secondthreshold regulates how close the measured flowrate must be to the sumof the appliances' baseline flowrates. That is, for the threshold periodof time, the system looks for a gas flowrate that is within anotherthreshold value of the sum of the appliances' baseline flowrates. In theevent of a failure, the system then reports the failure to a main officeor other system. In an environment of an under-sized service, severalfixed-rate consumers of gas (e.g., a hot water tank) may be operating atless than the sum of their actual fixed rates, due to the undersizednature of the service. Obviously, this is detrimental to the consumerand the appliance, and is identified by the techniques of the methods1400 and 1500.

In FIG. 14 at block 1402, gas consumption data, which is associated withan amount of gas consumed at a service point, is received. In anexample, the received gas consumption data includes, or is based atleast in part on, data including elapsed time between switch closures ofa gas metrology unit at the service point. In another example, thereceived gas consumption data includes, or is based at least in part on,flowrate data obtained from a solid-state metrology device.

At block 1404, the gas consumption data is disaggregated to identify aplurality of (e.g., two or more) baseline flowrates. The baselineflowrates may include the flowrates of several fixed-rate (or “regular”)consumers of gas, like many hot water tanks, hot tubs and furnaces. Inan example, the disaggregation may be performed by operation of all orpart of the system of FIG. 1, devices of FIGS. 2 and/or 3, and/or themethods of FIGS. 3-8. The disaggregation may be performed at a smartmetering device of the service point, at a remote server (e.g., of autility company), or any selected computing device. In an example, thedisaggregation process may include identifying baseline flowrates ofeach of a plurality of regular consumers of gas comprising fixed-gas-useappliances and/or identifying baseline flowrates of summations of two ormore of regular consumers of gas. Within the summations, the constituentappliances whose individual flowrates result in the summation may beidentified.

In an example, the disaggregation of gas usage may be performed usingnew gas consumption data to determine if new baseline flowrate(s) arepresent. In an example, the disaggregating includes identifying baselineflowrates of a plurality of consumers of gas comprising fixed-gas-useappliances and identifying a composite flowrate including a summation ofat least two fixed-gas-use appliances.

At block 1406, a first baseline flowrate of gas used by a first regularand/or fixed-rate consumer of gas is selected. In an example, a firstbaseline flowrate of gas used by a first appliance, or a flowrate thatrepresents gas used by two or more appliances, is selected from amongtwo or more baseline flowrates.

At block 1408, a second baseline flowrate of gas used by a secondregular and/or fixed-rate consumer of gas—which is not one of the two ormore appliances selected in block 1406 is selected from among theplurality of baseline flowrates. Baseline flowrates are the gasflowrates needed by respective fixed-rate consumers (e.g., appliances)of gas. In an example, the first and second baseline flowrates are thelargest two baseline flowrates. If the gas service is under-sized, itmay not be able to provide gas flow for the two largest baselineflowrates simultaneously. Accordingly, selection of the largest baselineflowrates provides a stronger test of the gas service to supplysufficient gas flow than selection of smaller baseline flowrates. Inanother example, baseline flowrates of all fixed-rate of gas consumptionappliances are selected. By selecting larger flowrates or flowrates ofall fixed-use appliances, the sum of block 1410 will be larger. Thelarger sum is a better test, at block 1412, to determine if the gasservice size is adequate.

At block 1410, the selected first and second flowrates of gas are addedtogether. The resulting sum is the flowrate associated with thesimultaneous use of the appliances associated with the flowratesselected at blocks 1406 and 1408. If, over a period of time, a flowrateequal or nearly equal to the sum is measured at the service point, thenit may be reasonably assumed that the appliances associated with theflowrates selected at blocks 1406, 1408 are operating simultaneously.Additionally, it may be assumed that each appliance is receiving theamount of gas that it received when other appliances were not also usinggas. This would suggest that the gas service is adequately sized.However, if a flowrate equal to the sum is not seen after monitoring fora period of time, that may indicate that the gas service is unable toprovide gas at the needed flowrate, i.e., the calculated sum.

At block 1412, after a period of time greater than a first thresholdvalue, the system or device performing method 1400 may fail to detectand/or confirm a third flowrate of gas measured at the service pointthat is within a second threshold value of the sum of the first baselineflowrate of gas and the second baseline flowrate of gas. In other words,after watching the gas flowrate at the service site for a reasonableperiod of time (e.g., possibly months, through summer and winter, and/orthrough an electrical power outage when a gas-powered generator might beused) the system fails to measure a gas flowrate that is nearly (e.g.,to within the second threshold value) equal to the sum of the firstflowrate and the second flowrate. That is, the system fails to confirmthat the two appliances (or groups of appliances) can operate at thesame time with each using the full value of their respective baselineflowrates. This indicates that the gas supply to the service point isinadequate.

In some instances, the baseline flowrate of more than two appliances maybe summed together to determine if the gas supply to the service isinadequate. In an example, all fixed-flowrate appliances are identified,and the techniques of block 1412 are applied. In a further example,combinations of gas flows of fixed flowrate appliances are tested atblock 1412. A combination of three fixed flowrate appliances may exceedthe service capacity at a service site, but simultaneous operation ofthe three appliances may happen with less frequency. Accordingly, thefirst threshold may have to be lengthened, when flowrates associatedwith a greater number of appliances are used in the summation of block1410.

At block 1414, the system reports and/or corrects the inadequate gassupply to the service point. In an example, the system operating themethod 1400 may determine a maximum flowrate over an interval of timeand compare the maximum flowrate to the sum of the first baselineflowrate of gas and the second baseline flowrate of gas. In the example,the reporting may include the maximum flowrate measured over aninterval, the first baseline flowrate, and/or the second baselineflowrate (and other baseline rates, e.g., if used in the summation thatexceeded the service size). If the maximum flowrate measured over aninterval of time is less than the sum of two or more baseline flowrates,then the amount by which the maximum flowrate is less than the sum mayindicate a minimum amount by which the supply rate should be expanded atthe service point. The service site may be replaced to include largergas pipes, a larger gas meter, and/or other equipment and/orinfrastructure to provide more gas and/or greater a gas flowrate to theservice site.

In some examples, before reporting and/or correcting the inadequate gassupply to the service point, the method 1400 may include the steps ofperforming a further disaggregation and confirming that the firstbaseline flowrate and the second baseline flowrate are still present.This would prevent reporting of a problem with a service size when noneexisted.

Example Recognition of Under-Sized Gas Capacity at Service Point

FIG. 15 shows an example method 1500 to determine if a gas service isadequately sized. At block 1502, first flowrate informationcorresponding to gas usage at a service site may be obtained over afirst period of time.

At block 1504, the first flowrate information may be disaggregated todetermine an expected flowrate associated with each of two or moreappliances having a generally fixed-rate of gas consumption.

At block 1506, second flowrate information corresponding to may beobtained over a second period of time.

At block 1508, the second flowrate information corresponding to thesecond period of time may be compared to one or more combinations of theexpected flowrate associated with each of the two or more appliances.

At block 1510, based on the comparison, it may be determined that gaspiping or a gas meter at the service site is not appropriately sized. Inan example, two fixed-rate of gas-consumption appliances may operate atthe same time. If the gas service is adequately sized, then the gasflowrate would be the sum of the two fixed-rate appliances (at timeswhen other appliances are not operating). However, if that condition isnever seen (i.e., a gas flowrate equal to the sum of the two fixed-ratevalues is not detected) then it is possible that the service to the siteis undersized. In some examples, blocks 1502-1510 and/or blocks1506-1510 may be repeated one or more times to determine if the gasservice is, or has become, undersized. By repeating the disaggregationblock 1504, any newly added fixed-rate gas-consuming appliance will beidentified.

At block 1512, a notification may be generated, and may be based, atleast in part, on the determination that the service at the customer'ssite is undersized.

At block 1514, the notification may be transmitted to another device. Inexamples, the message or notification may be transmitted to the customerand/or the gas utility company. In another example, the gas utilitycompany and/or their agent may fix the gas service size, such as bychanging to larger pipes and/or changing to a larger gas meter, and/orby making other appropriate changes.

Example Recognition of Under-Sized Gas Capacity at Service Point

The following numbered clauses include additional examples to determineif a gas service is adequately sized.

1. A method, comprising: obtaining first flowrate informationcorresponding to gas usage at a service site over a first period oftime; disaggregating the first flowrate information to determine anexpected flowrate associated with each of two or more appliances havinga generally fixed-rate of gas consumption; obtaining second flowrateinformation corresponding to a second period of time; comparing thesecond flowrate information corresponding to the second period of timeto one or more combinations of the expected flowrate associated witheach of the two or more appliances; determining, based on thecomparison, that gas piping or a gas meter at the service site is notappropriately sized; generating a notification based, at least in part,on the determining; and transmitting the notification to another device.

2. The method of clause 1, wherein the one or more combinationscomprise: a sum of two or more of the expected flowrates associated withrespective appliances of the two or more appliances.

3. The method of clause 1, wherein at least one of the two or moreappliances having generally fixed-rate gas consumption is a gas hotwater tank.

4. The method of clause 1, wherein the comparing comprises calculating adifference between: the second flowrate information corresponding to thesecond period of time; and the one or more combinations of the expectedflowrate associated with each of the two or more appliances.

5. The method of clause 1, wherein disaggregating the first flowrateinformation to determine the expected flowrate associated with each ofthe two or more appliances comprises: excluding flowrates associatedwith appliances that have variable gas flowrates.

6. The method of clause 1, wherein obtaining the first flowrateinformation and obtaining the second flowrate information comprises:obtaining the second flowrate information after a threshold period oftime has elapsed following obtaining the first flowrate information.

7. The method of clause 1, wherein aspects of the method are performedat a computing device at the service site.

8. The method of clause 1, wherein aspects of the method are performedat a computing device that is remote from the service site.

9. The method of clause 1, wherein the notification comprises arecommendation to upgrade a service at the service site, and wherein themethod additionally comprises: upgrading the service at the service siteto provide a greater gas flowrate than an original service at theservice site, wherein the upgrading comprises changing at least one of apipe size of incoming gas or a meter size at the service site.

10. One or more computer-readable media storing computer-executableinstructions that, when executed by one or more processors, configure acomputing device to perform acts comprising: obtaining first flowrateinformation corresponding to gas usage at an endpoint corresponding to aservice site over a first period of time; disaggregating the firstflowrate information to determine an expected flowrate associated witheach of two or more appliances having a generally fixed-rate of gasconsumption; obtaining second flowrate information corresponding to asecond period of time; comparing the second flowrate informationcorresponding to the second period of time to one or more combinationsof the expected flowrate associated with each of the two or moreappliances; determining, based on the comparison, that gas piping or agas meter at the service site is not appropriately sized; generating anotification based, at least in part, on the determining; andtransmitting the notification to another device.

11. One or more computer-readable media as recited in clause 10, whereinthe disaggregating comprises: excluding flowrates associated withappliances that have variable gas flowrates.

12. One or more computer-readable media as recited in clause 10, whereinthe disaggregating comprises: identifying all single-appliance baselineflowrates of fixed-rate gas appliances operating at the service site.

13. One or more computer-readable media as recited in clause 10, whereinthe second flowrate information does not match flowrates of anycombinations of the two or more appliances.

14. One or more computer-readable media as recited in clause 10, whereinthe comparing identifies a combination of appliances having a combinedflowrate of gas that is greater than all flowrates included in thesecond flowrate information.

15. One or more computer-readable media as recited in clause 10, whereinthe comparing comprises calculating a difference between: the secondflowrate information corresponding to the second period of time; and theone or more combinations of the expected flowrate associated with eachof the two or more appliances.

16. A system, comprising: a metering device to meter gas usage at aservice point and to send data; and a headend to receive the data,wherein the data comprises: consumption data; and timing data indicatingduration of a plurality of time intervals between switch closures of themetering device, wherein each switch closure indicates measurement of aunit volume of gas; wherein the headend comprises a processor and memoryconfigured with instructions, which when executed perform actscomprising: obtaining first flowrate information corresponding to gasusage at an endpoint corresponding to a service site over a first periodof time; disaggregating the first flowrate information to determine anexpected flowrate associated with each of two or more appliances havinga generally fixed-rate of gas consumption; obtaining second flowrateinformation corresponding to a second period of time; comparing thesecond flowrate information corresponding to the second period of timeto one or more combinations of the expected flowrate associated witheach of the two or more appliances; determining, based on thecomparison, that gas piping or a gas meter at the service site is notappropriately sized; generating a notification based, at least in part,on the determining; and transmitting the notification to another device.

17. The system of clause 16, wherein disaggregating gas usage at theservice point comprises: identifying flowrates of all appliances havingfixed-flowrates of gas operating at the service point.

18. The system of clause 16, wherein the comparing comprises: comparingthe second flowrate information to a sum of flowrates associated withall fixed-rate appliances identified by the disaggregation.

19. The system of clause 16, wherein the comparing comprises:determining that the second flowrate information does not matchflowrates associated with any combination of fixed-rate appliancesidentified by the disaggregation.

20. The system of clause 16, wherein the determining that gas piping orthe gas meter at the endpoint are not appropriately sized comprises:determining that one or more of the gas piping or the gas meter at theservice site is too small for the service point.

Example Recognition of Low Gas Pressure Supply at Service Point

FIGS. 16-18 show example methods 1600, 1700, 1800 to determine if one ormore service sites are experiencing a low gas-pressure condition, i.e.,lower than desired or designed gas pressure is presented to the meter ofa service site by the piping of the system. Such a condition may resultfrom a leak in the area or from higher than normal consumption of gas bythe service site(s) in an area.

While an order of the blocks of the method is shown, some variation inthe order of execution may be made without departing from the scope ofthe method as disclosed or claimed. The methods may be performed by anydevice, such as those having a processor and memory. In severalexamples, the methods may be performed by a smart gas meter, e.g., asmart meter associated with node 108 of FIG. 1. The method may beperformed by computer devices within the central office 106, acloud-based computing service, or other computing device, etc. Themethods may be performed by a headend device, a service point (e.g.,smart gas meter) or performed by a combination of devices. In anexample, the methods may be performed by execution of software or anapplication running on a smart meter, central office server, or otherdevice. In the examples of FIG. 1, the techniques 130 may include and/orbe configured as an application able to execute the methods. In theexamples of FIGS. 2 and 3, the methods may be performed by softwarestored in memory device 216 and executed by a processing device and/orprocessor 214.

Utility companies attempt to maintain a stable and prescribed level (orrange) of gas pressure at the meter of each service point. This levelprovides customers with optimal service. However, gas usage may increaseat certain times, such as during particularly cold weather. Similarly, agas leak may lower gas pressure in an area of several metering devices.The techniques discussed herein identify service sites or regions ofservice sites where the prescribed level of gas pressure has fallen,thereby creating a low gas-pressure condition. The techniques describedherein allow detection of such condition without the use of gas pressuresensors, which are typically unavailable in many or most locations of agas supply system. That is, in many gas-supply systems, metrologydevices are configured to measure a quantity of gas flow and cumulativegas consumption, but do not measure gas flowrate or gas pressure. Thisis particularly true of mechanical metrology devices that are widespreadin many regions of the country and world.

In an example, a system is configured to perform the techniquesdiscussed herein. The system may disaggregate gas usage at a servicepoint to determine a baseline (or reference) rate of gas consumption byan appliance that consumes fixed gas flowrate. As the system operates,it measures and/or obtains data indicating that a flowrate of gas at aservice point is within a first threshold value of the baseline flowrateof gas, indicating that the appliance is operating but other appliancesare not operating. Accordingly, the flowrate indicates use of gas by thefixed-flowrate appliance having the baseline gas use rate. The systemobtains a delta value indicating a magnitude by which the measuredflowrate of gas is less than the baseline flowrate of gas at the servicepoint. Thus, the system may subtract the flowrate from the baseline ofthe appliance, obtaining a positive “delta” value indicating an amountby which the fixed-flowrate appliance is being “starved” for gas. Thesystem compares the delta value to a second threshold value to determineif the magnitude of the delta value indicates a low gas-pressurecondition at the service point, i.e., if the delta is large enough inmagnitude to indicate a problem. If the flowrate is enough below thebaseline (i.e., if the “delta” is large enough), it may indicate a lowgas-pressure condition. The system may receive information from a groupof service points connected to a same gas supply pipe as the servicepoint. The information from each service point may include a measure bywhich a measured flowrate is less than a baseline flowrate of afixed-flowrate appliance at the service point. Thus, the system checksother service points to see if they have appliances that are operatingon less than normal gas usage rates. Accordingly, the system maydetermine that a region of low gas-pressure exists at the group ofservice points based at least in part on the received information.Responsive to a positive determination of existence of the region of lowgas-pressure the system may report the condition and/or performcorrective measures, such as attaching portable gas sources (e.g., gastanker trucks) to appropriate gas mains.

At block 1602, gas consumption data associated with an amount of gasconsumed at a service point is received. Upon receipt at a processinglocation, the gas consumption data may be disaggregated to revealbaseline flowrates of some or all fixed gas flowrate appliances. In anexample, the receipt of the data and/or the disaggregating may beperformed by operation of any part(s) of the system of FIG. 1, devicesof FIGS. 2 and/or 3, and/or the methods of FIGS. 3-8. The baseline (orreference) gas flowrate is the gas flowrate of an appliance that is aregular consumer of gas. Appliances that may have regular flowratesinclude many hot water tanks and furnaces.

At block 1604, a baseline flowrate of gas that is used by a regularconsumer (i.e., a fixed gas flowrate consumer, such as an appliance) ofgas is determined, based at least in part on the disaggregating. Theregular consumer of gas may be a hot water tank, a gas furnace, or thehot water tank and the furnace in simultaneous operation.

At block 1606, a flowrate of gas measured at the service point isobtained that is within a first threshold value of the baseline flowrateof the appliance. In an example, the flowrate of gas may be obtained bya smart metering device (e.g., if metrology device 126 of FIG. 1 is asmart or solid-state device). Alternatively, the flowrate of gas may beobtained or calculated by a remote computing device (e.g., the server106 of FIG. 1) if the metrology device 126 is a mechanical device. In anexample, a metrology module may detect a flowrate of gas that is closeenough (i.e., within the threshold value) to a known baseline flowrateof a fixed gas flowrate appliance to assume that the measured flowrateindicates operation of the regular consumer of gas (i.e., theappliance). In an example, the system may compare the obtained flowrateof gas to each of a plurality of baseline flowrates associated with arespective plurality of regular consumers of gas at the service point.The plurality of baseline flowrates may be stored on the smart meteringdevice (e.g., at consumption log 226) or may be stored at a remoteserver. The comparisons may result in a match of the measured flowrateof gas to the appliance to within the first threshold value.

In some older metering devices, obtaining the flowrate of gas measuredat the service point may include measuring time(s) between switchclosures of a gas meter or metrology device at the service point. Innewer solid-state metering devices, the flowrate may be obtaineddirectly from the metrology device.

At block 1608, a delta value indicating that the flowrate of gas that isless than the baseline flowrate of gas at the service point is obtained.In an example, the measured flowrate of gas is less than the baselinegas flowrate of the appliance or other regular consumer of gas. Theamount by which the measured flowrate is less than the baseline flowratemay be called the “delta,” and may indicate that the appliance is notable to receive its baseline flowrate of gas. That is, the appliance isbeing “starved” for gas by a low gas-pressure event or condition whereinless than the prescribed gas pressure is received by the gas meter ofthe service site of the appliance.

At block 1610, the delta value is compared to a second threshold value.A delta of sufficient magnitude—that exceeds the threshold value—mayindicate that the appliance is not receiving the gas flowrate that itrequires as a fixed gas flowrate appliance.

The delta value indicates an amount by which the measured flowrate ofgas is less than the baseline flowrate of gas for an appliance. In someexamples, the delta value may be a scalar value, which is compared to ascalar threshold value. In other examples, a plurality of measurementsallows calculation of a standard deviation. In a specific example, ifthe baseline flowrate is within one standard deviation, a lowgas-pressure condition is not indicated; otherwise, the low gas-pressurecondition is indicated.

At block 1612, responsive to the delta value exceeding the secondthreshold value, it is determined if a low gas-pressure condition existsat the service site. In an example, if a fixed gas flowrate appliance isusing less gas than its baseline flowrate, and the amount by which usageis less is greater than the delta value, then it may be assumed that alow gas-pressure condition is present at the service site. Some or allof the operations 1602-1612 may have been performed at a smart meteringdevice and/or at a remote server and/or data processing device. In someinstances, data may be sent over a network to or from an analyticsapplication. The data may include an identification of the service pointand the delta value or information from which the delta value may bederived. In other instances, a message may be sent announcing the lowgas-pressure condition.

At block 1614, delta values from other service points supplied by a gaspipeline that supplies the service point are compared to a thresholdvalue (e.g., the threshold value of block 1610 or a different thresholdvalue). In an example, a low gas-pressure condition may be local to theservice point discussed with respect to blocks 1602-1612. Alternatively,the low gas-pressure condition may involve a plurality of service pointsand/or customers.

At block 1616, if the delta values of the other service points exceededthe threshold value, then a regional low gas-pressure condition or eventmay be determined, reported and addressed. In an example, thelow-pressure region may be re-pressurized. Depending on the size of theregion and the gas pressure, an additional quantity of gas may be sentto the region. The quantity of gas may be based at least in part on oneor more delta values from a respective one or more service points. Thatis, the quantity of gas may be based on how much the gas pressure isbelow a preferred level.

Method 1600 may be performed using data generated from two or more gasmetering devices. Accordingly, the service point described above withrespect to blocks 1602-1612 may be considered a first service point. Inan example, a second service point performs the same or similar actions.In a further example, the second service point may perform the actionsat times that are offset from the actions performed by the first servicepoint. Advantageously, by using offset timing, a low gas-pressurecondition may be recognized by one meter at a time that another meter isconserving battery power and not making calculations. In an example, ifone meter recognizes a possible low gas-pressure condition, another gasmeter may wake from a battery power conservation mode to try to confirmthe low gas-pressure condition.

Method 1600 may be performed at regular intervals, at random intervalsor other intervals. In an example that may save battery power, gas flowmay be measured at a metrology device of the service point at timesbased at least in part on expected times of operation of the regularconsumer(s) of gas.

Example Recognition of Low Gas Pressure Supply at Service Point

FIG. 17 shows an example method 1700 to determine if two or more servicesites are experiencing a low gas-pressure condition, i.e., lower thandesired or designed gas pressure is presented to the meter of a servicesite by the piping of the system.

At block 1702, a flowrate of gas at a first device is obtained. In anexample, the first device may be a gas meter at a first gas servicesite, i.e., a customer's location.

At block 1704, the flowrate of gas may be disaggregated to obtain arepresentation of a flowrate of gas corresponding to an appliance havinga generally fixed-rate of gas consumption.

At block 1706, based at least in part on the representation of theflowrate of gas corresponding to the appliance, and based at least inpart on a representation of historical gas flowrate to the appliance, itmay be determined that gas pressure at the first device is lower thanexpected.

At block 1708, information from a second device indicative of its gaspressure may be obtained. In an example, the second device may be a gasmeter at a second gas service site. A disaggregation of the gas flow ofthe second service site may indicate that a fixed-rate ofgas-consumption appliance is using too little gas; that is, the serviceis unable to provide the accustomed flowrate to the appliance.

At block 1710, based on the gas pressure at the first device being lowerthan expected and based on the obtained information from the seconddevice indicative of its gas pressure, it is determined whether a lowgas pressure situation exists in a regional area. If one servicelocation had low gas pressure, it could be indicative of either acustomer that had added appliances and outgrown the service at theservice site, or a low gas-pressure condition in a region. If twoservice sites are seeing low gas pressure, it is likely that a low gaspressure condition exists in a region.

At block 1712, a message is generated, e.g., based on the determinationat block 1710. The message may include data such as the (low) gaspressures and identifications of the respective service sitesexperiencing those conditions.

At block 1714, the message is transmitted, e.g., from service site(s) toutility company headend, or within servers of the headend. As indicatedat block 1810 (FIG. 18) the region of low pressure can then bere-pressurized, such as by operation of control circuits of the headendand/or by settings and valves operated by utility work crew members.

Example Recognition of Low Gas Pressure Supply at Service Point

FIG. 18 shows an example method 1800 to determine if two or more servicesites are experiencing a low gas-pressure condition, i.e., lower thandesired or designed gas pressure is presented to the meter of a servicesite by the piping of the system. At block 1802, a first indication of afirst potential low gas pressure condition is acquired at a firstservice site. At block 1804, a second indication of a second potentiallow gas pressure condition is acquired at a second service site. In anexample, the first and second indications may be based at least in parton gas flowrates, rather than pressure measurements. The gas flowratesmay be based on gas being used by one or more fixed-rate ofgas-consumption appliances in each of the two service sites. The gasflowrates to the fixed-rate of gas-consumption appliances may be basedon disaggregation of a gas flow to a respective service site.

At block 1806, based at least in part on the first indication and basedat least in part on the second indication, it may be determined whethera low-pressure condition is present for a region of the first and secondservice sites. In the example of block 1808, flowrates of gas may bedisaggregated to check for low gas pressure at each of the first andsecond service sites.

At block 1810, one or more actions may be taken in response to thedetermination that a low-pressure gas region includes at least the firstand second service sites. In one example, a message reporting the lowgas pressure of the first and second service sites may be transmitted,such as to a utility company, governmental entity, etc. In anotherexample, the region of low gas pressure may be re-pressurized. There-pressurization may be performed by a gas utility company, which maysend additional gas to the region.

Example Recognition of Low Gas Pressure Supply at Service Point

The following numbered clauses include additional examples to determineif one or more service sites are experiencing a low gas-pressurecondition.

1. A method, comprising: obtaining a flowrate of gas at a first device;disaggregating the flowrate of gas to obtain a representation of aflowrate of gas corresponding to an appliance having a generallyfixed-rate of gas consumption; determining, based at least in part onthe representation of the flowrate of gas corresponding to theappliance, and based at least in part on a representation of historicalgas flowrate to the appliance, that gas pressure at the first device islower than expected; obtaining information from a second deviceindicative of its gas pressure; determining, based on the gas pressureat the first device being lower than expected and based on the obtainedinformation from the second device indicative of its gas pressure,whether a low gas pressure situation exists in a regional area;generating a message, based at least in part on the determination; andtransmitting the message.

2. The method of clause 1, wherein: the method is performed by a headenddevice; or the method is performed at least in part by an endpointassociated with a gas service site.

3. The method of clause 1, wherein transmitting the message comprises atleast one of: transmitting the message to a headend device; transmittingthe message to an endpoint associated with a gas service; ortransmitting the message to service personnel.

4. The method of clause 1, wherein the message tells a headend devicethat an endpoint associated with a gas service site is experiencing lowgas pressure.

5. The method of clause 1, wherein determining whether the low gaspressure situation exists for the regional area comprises: determiningthat the flowrate of gas corresponding to the appliance is less than therepresentation of historical gas flowrate by the appliance.

6. The method of clause 1, wherein determining whether the low gaspressure situation exists for the regional area comprises: determiningif at least one fixed-rate gas appliance in each of at least two servicelocations has a lower than historical flowrate.

7. The method of clause 1, additionally comprising: determining if a gaspipeline serves at least one fixed-rate gas appliance having a lowerthan historical flowrate in each of at least two service locations.

8. The method of clause 1, wherein: the method is performed at least inpart by a first endpoint and performed at least in part by a secondendpoint; and the first endpoint and the second endpoint are on a samegas supply pipeline.

9. The method of clause 8, additionally comprising: re-pressurizing alow gas-pressure area using a quantity of gas based at least in part ona size of the regional area affected by low gas pressure.

10. The method of clause 1, wherein: the method is performed by a firstendpoint and performed by a second endpoint; and the first endpoint andthe second endpoint are on a same gas supply pipeline.

11. A gas meter, comprising: a processor; a metrology unit controlled bythe processor; a radio controlled by the processor; and a memory devicein communication with the processor, and containing statements, whichwhen executed by the processor perform actions comprising: obtaining aflowrate of gas at a first device; disaggregating the flowrate of gas toobtain a representation of a flowrate of gas corresponding to anappliance having a generally fixed-rate of gas consumption; determining,based at least in part on the representation of the flowrate of gascorresponding to the appliance, and based at least in part on arepresentation of historical gas flowrate to the appliance, that gaspressure at the first device is lower than expected; obtaininginformation from a second device indicative of its gas pressure;determining, based on the gas pressure at the first device being lowerthan expected and based on the obtained information from the seconddevice indicative of its gas pressure, whether a low gas pressuresituation exists in a regional area; generating a message, based atleast in part on the determination; and transmitting the message.

12. The gas meter of clause 11, wherein the message is transmitted to asecond gas meter, and wherein the message indicates a need for thesecond gas meter to determine if it is within the low gas pressuresituation.

13. The gas meter of clause 11, wherein the message is transmitted to aheadend device, and wherein the message indicates that the gas meter iswithin the regional area.

14. The gas meter of clause 11, wherein the message is updated when thegas meter is no longer associated with the low gas pressure situation.

15. The gas meter of clause 11, wherein the memory device contains atleast one representation of historical gas flowrate of at least oneappliance.

16. A method, comprising: acquiring a first representation of a firstflowrate at a first service site; acquiring a second representation of asecond flowrate at a second service site; determining, based at least inpart on the first representation, and based at least in part on thesecond representation, whether a low-pressure condition is present for aregion; and taking an action to overcome the low-pressure condition.

17. The method of clause 16, wherein: the method is performed by aheadend device; or the method is performed by an endpoint associatedwith a gas service site.

18. The method of clause 16, wherein the action comprises one or moreof: sending a message indicating a possible need to re-pressurize gas inthe region; and re-pressurizing the region to overcome the low-pressurecondition.

19. The method of clause 16, wherein: acquiring the first representationcomprises disaggregating a flowrate of gas of the first service site toobtain the first representation, wherein the first representationcomprises gas used by an appliance at the first service site having agenerally fixed-rate of gas consumption; and acquiring the secondrepresentation comprises disaggregating a flowrate of gas of the secondservice site to obtain the second representation, wherein the secondrepresentation comprises gas used by an appliance at the second servicesite having a generally fixed-rate of gas consumption.

20. The method of clause 16, wherein the method additionally comprises:disaggregating flowrates at the first service site and at the secondservice site to obtain: the first flowrate at the first service site,wherein the first flowrate represents gas used by a first generallyfixed-rate of gas use appliance at the first service site; and thesecond flowrate at the second service site, wherein the second flowraterepresents gas used by a second generally fixed-rate of gas useappliance at the second service site; obtaining gas pressure informationbased at least in part on the first flowrate, the second flowrate, andhistorical gas usage at the first service site and the second servicesite.

CONCLUSION

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described. Rather,the specific features and acts are disclosed as exemplary forms ofimplementing the claims.

What is claimed is:
 1. A method, comprising: obtaining a flowrate of gasby a device at a service site; disaggregating the flowrate of gas toobtain a representation of a flowrate of gas corresponding to anappliance having a generally fixed-rate of gas consumption; comparingthe representation of the flowrate of gas corresponding to the applianceto a representation of historical gas consumption by the appliance;determining, based at least in part on the comparing, that performanceof the appliance has changed over time; generating a notification, basedat least in part on the determination; and transmitting the notificationto another device.
 2. The method of claim 1, wherein the disaggregating,comparing and determining are performed at: a server at a centraloffice; or a data processing component of the device at the servicesite.
 3. The method of claim 1, wherein obtaining the flowrate of gas atthe service site comprises: obtaining data regarding time between switchclosures; obtaining data regarding a number of switch closures overtime; or obtaining data from a metrology device that can directlymeasure the flowrate of gas.
 4. The method of claim 1, wherein therepresentation of historical gas consumption by the appliance comprises:a record of gas consumption and a record of corresponding environmentalconditions.
 5. The method of claim 1, additionally comprising: selectingthe representation of historical gas consumption by the appliance basedat least in part on environmental conditions.
 6. The method of claim 1,wherein comparing the representation of the flowrate of gascorresponding to the appliance to the representation of historical gasconsumption by the appliance comprises: compensating for differences inenvironmental conditions at times the two flowrates were measured. 7.The method of claim 1, wherein determining that performance of theappliance has changed over time comprises: determining that a durationof a period of usage has changed compared to the representation ofhistorical gas consumption by the appliance.
 8. The method of claim 1,wherein determining that performance of the appliance has changed overtime comprises: determining that a time between periods of usage haschanged compared to the representation of historical gas consumption bythe appliance.
 9. The method of claim 1, wherein determining thatperformance of the appliance has changed over time comprises:determining that an amplitude of usage has changed compared to therepresentation of historical gas consumption by the appliance.
 10. Themethod of claim 1, wherein determining that performance of the appliancehas changed over time comprises: determining that a peak amplitude ofusage has changed compared to the representation of historical gasconsumption by the appliance.
 11. The method of claim 1, wherein thetransmitting the notification to another device comprises transmittingthe notification to an in-home device.
 12. A headend device, comprising:a processor; a network connection; and one or more computer-readablemedia storing computer-executable instructions that, when executed bythe processor, configure the headend device to perform operationscomprising: obtaining a flowrate of gas; disaggregating the flowrate ofgas to obtain a representation of a flowrate of gas corresponding to anappliance having a generally fixed-rate of gas consumption; comparingthe representation of the flowrate of gas corresponding to the applianceto a representation of historical gas consumption by the appliance;determining, based at least in part on the comparing, that performanceof the appliance has changed over time; and sending a message indicatingrepair or replacement of the appliance, consistent with the determining,is indicated.
 13. The headend device as recited in claim 12, whereindisaggregating the flowrate of gas comprises: adjusting a disaggregationfunction based at least in part on historical data indicating a changein gas consumption of the appliance over time.
 14. The headend device asrecited in claim 12, wherein the appliance is located at a first servicepoint, and wherein the comparing additionally comprises: comparing therepresentation of the flowrate of gas corresponding to the appliance toa representation of gas consumption by an appliance at a second servicepoint.
 15. The headend device as recited in claim 12, wherein therepresentation of historical gas consumption by the appliance comprisesat least one of: a representation of ambient air temperature; arepresentation of incoming gas temperature; and a representation ofincoming water temperature.
 16. One or more computer-readable mediastoring computer-executable instructions that, when executed by one ormore processors, configure a computing device to perform actscomprising: obtaining a flowrate of gas; disaggregating the flowrate ofgas to obtain a representation of a flowrate of gas corresponding to anappliance having a generally fixed-rate of gas consumption; comparingthe representation of the flowrate of gas corresponding to the applianceto a representation of historical gas consumption by the appliance;determining, based at least in part on the comparing, that performanceof the appliance has changed over time; generating a notification, basedat least in part on the determination; and transmitting the notificationto another device.
 17. One or more computer-readable media as recited inclaim 16, wherein determining that performance of the appliance haschanged over time comprises: determining that a duration of a period ofusage has changed compared to the representation of historical gasconsumption by the appliance.
 18. One or more computer-readable media asrecited in claim 16, wherein determining that performance of theappliance has changed over time comprises: determining that a timebetween periods of usage has changed compared to the representation ofhistorical gas consumption by the appliance.
 19. One or morecomputer-readable media as recited in claim 16, wherein determining thatperformance of the appliance has changed over time comprises:determining that an amplitude of usage has changed compared to therepresentation of historical gas consumption by the appliance.
 20. Oneor more computer-readable media as recited in claim 16, wherein therepresentation of historical gas consumption by the appliance comprisesat least one of: a representation of ambient air temperature; arepresentation of incoming gas temperature; and a representation ofincoming water temperature.